package com.flyway.handles;

import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.exceptions.JWTVerificationException;
import com.flyway.anno.PassToken;
import com.flyway.anno.UserLoginToken;
import com.flyway.pojo.Users;
import com.flyway.service.UserService;
import com.flyway.utils.TokenUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Method;

/**
 * @Description: 权限拦截器
 * @Author: xupx
 * @Date: 2019/11/15
 */
public class AuthenticationInterceptor implements HandlerInterceptor {
    @Autowired
    private UserService userService;
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object object) throws Exception {
        // 从 http 请求头中取出 token
        String token = httpServletRequest.getHeader("token");
        // 如果不是映射到方法直接通过
        if (!(object instanceof HandlerMethod)) {
            return true;
        }
        HandlerMethod handlerMethod = (HandlerMethod) object;
        Method method = handlerMethod.getMethod();
        //检查是否有passtoken注释，有则跳过认证
        if (method.isAnnotationPresent(PassToken.class)) {
            PassToken passToken = method.getAnnotation(PassToken.class);
            if (passToken.required()) {
                return true;
            }
        }
        // 执行认证
        if (token == null) {
            throw new RuntimeException("无token，请重新登录");
        }
        // 获取 token 中的 user id
        String userId;
        try {
            userId = JWT.decode(token).getAudience().get(0);
        } catch (JWTDecodeException j) {
            throw new RuntimeException("401");
        }
        if(null == userId){
            throw new RuntimeException("用户不存在，请重新登录");
        }
        Integer id;
        try {
             id = Integer.parseInt(userId);
        }catch (Exception e){
            throw new RuntimeException("用户信息不存在");
        }
        Users user = userService.findUserById(id);
        if (user == null) {
            throw new RuntimeException("用户不存在，请重新登录");
        }
        try {
            // 验证 token
            TokenUtils.checkToken(user.getPassword(),token);
        } catch (JWTVerificationException e) {
            throw new RuntimeException("401");
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest,
                           HttpServletResponse httpServletResponse,
                           Object o, ModelAndView modelAndView){

    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest,
                                HttpServletResponse httpServletResponse,
                                Object o, Exception e){
    }
}